Filmes ultrafinos de ésteres de celulose: preparo, caracterização e imobilização de proteínas

Amim, Jorge; Petri, Denise Freitas Siqueira; Maia, Francisco; Miranda, Paulo B.

doi:10.1590/s0100-40422010001000011

Cited by 11 publications

(2 citation statements)

References 24 publications

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“…These include, e.g., thickeners in cosmetics and food products; membranes for drug release, adhesives and biomolecule immobilization [40,41,42,43]. The final properties of the cellulose acetate have a direct dependence on the method of synthesis, the degree of substitution and thus the uniformity of the distribution of the acetate groups in the anhydroglucose unit and along the cellulose backbone .…”

Section: Introductionmentioning

confidence: 99%

Bio-based Films from Linter Cellulose and Its Acetates: Formation and Properties

et al. 2013

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This paper describes the results obtained on the preparation of films composed of linter cellulose and the corresponding acetates. The acetylation was carried out in the LiCl/DMAc solvent system. Films were prepared from a LiCl/DMAc solution of cellulose acetates (degree of substitution, DS 0.8–2.9) mixed with linter cellulose (5, 10 and 15 wt %). Detailed characterization of the films revealed the following: (i) they exhibited fibrous structures on their surfaces. The strong tendency of the linter cellulose chains to aggregate in LiCl/DMAc suggests that these fibrous elements consist of cellulose chains, as can be deduced from SEM images of the film of cellulose proper; (ii) the cellulose acetate films obtained from samples with DS 2.1 and 2.9 exhibited microspheres on the surface, whose formation seems to be favored for acetates with higher DS; (iii) AFM analysis showed that, in general, the presence of cellulose increased both the asperity thickness and the surface roughness of the analyzed films, indicating that cellulose chains are at least partially organized in domains and not molecularly dispersed between acetate chains; and (iv) the films prepared from cellulose and acetates exhibited lower hygroscopicity than the acetate films, also suggesting that the cellulose chains are organized into domains, probably due to strong intermolecular interactions. The linter and sisal acetates (the latter from a prior study), and their respective films, were prepared using the same processes; however, the two sets of films presented more differences (as in humidity absorption, optical, and tensile properties) than similarities (as in some morphological aspects), most likely due to the different properties of the starting materials. Potential applications of the films prepared in tissue engineering scaffold coatings and/or drug delivery are mentioned.

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Section: Introductionmentioning

confidence: 99%

Bio-based Films from Linter Cellulose and Its Acetates: Formation and Properties

et al. 2013

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“…Lopez et al (1997) defined immobilization as the process by which particles are attached or entrapped, which is basically applied to all types of biocatalysts including, cellular organelles, enzymes, and plant and animal cells. Immobilization of cells is one of the methods employed in the field of biotechnology to improve amino acid production (Amin et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

L-glutamic acid production by immobilized wild and mutant Bacillus species

Durojaye¹,

Adebayo-Tayo²,

Onifade³

2023

J. Biosci. Biotechnol. Discov.

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The effect of Ultra-Violet (UV) irradiation and acridine orange dye on L-glutamic acid producing Bacillus subtilis and B. megaterium was investigated. The selected mutant strains and wild types of B. subtilis and B. megaterium were immobilized and used for L-glutamic acid production. The Bacillus strains were exposed to UV irradiation and treated with acridine orange dye respectively. The survived Bacillus strains were found to reduce as the exposure time and concentration of the mutagens increased in this study. Four mutants of B. subtilis and two mutants of B. megaterium were selected for L-glutamic acid production. Mutant strain of B. subtilis (MAIR4) treated with acridine orange dye yielded the highest L-glutamic acid (4.62 mg/mL) at 72 hours. L-glutamic acid production by mutant wild and strains of B. subtilis and B. megaterium immobilized on sodium alginate, Agar-agar matrix and poly urethane foam ranged from 1.65 to 4.03 mg/mL, 2.04 to 3.98 mg/ mL and 1.89 to 3.39 mg/mL, respectively with B. megaterium (MUSO17) on sodium alginate producing the highest L-glutamic acid. Sodium alginate was the best supporting matrix for the production of L-glutamic acid in this research. Immobilization of mutant strains of Bacillus megaterium (MASO17) exposed to UV irradiation using sodium alginate supported the L-glutamic acid production.

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Effect of sorbitan-based surfactants on glass transition temperature of cellulose esters

Amim

Blachechen

Petri

2011

J Therm Anal Calorim

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Filmes ultrafinos de ésteres de celulose: preparo, caracterização e imobilização de proteínas

Cited by 11 publications

References 24 publications

Bio-based Films from Linter Cellulose and Its Acetates: Formation and Properties

Bio-based Films from Linter Cellulose and Its Acetates: Formation and Properties

L-glutamic acid production by immobilized wild and mutant Bacillus species

Effect of sorbitan-based surfactants on glass transition temperature of cellulose esters

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